发表机构
California Institute of Technology/IPAC; Armagh Observatory & Planetarium; Technische Universität Braunschweig; University of Central Florida; University of Maryland, College Park; University of California, Los Angeles（加州理工学院/IPAC; 阿马天文台和天文馆; 布伦瑞克工业大学; 中佛罗里达大学; 马里兰大学帕克分校; 加利福尼亚大学洛杉矶分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
基于WISE/NEOWISE数据，测量523颗彗星核大小与颜色，给出大小频率分布斜率，揭示彗核物理特性及与海王星外天体演化的联系。
AI 中文摘要
彗核保存了星子形成过程的记录，但由于彗核通常与其彗发混合在一起，其大小难以测量。我们基于14.5年的WISE/NEOWISE档案数据，并辅以斯皮策（Spitzer）光度测量，给出了523颗彗星（235颗长周期彗星和288颗短周期彗星；LPCs和SPCs）的彗核大小目录。对径向轮廓进行彗发-彗核分解，为全部523颗彗星提供了保守的上限值，并为其中301颗（107颗LPCs和194颗SPCs）提供了具有不确定性的直径，其中位直径分别为5.3公里和2.5公里。在四个WISE波段中，彗核颜色遵循从反射辐射过渡到热辐射所预期的日心距趋势，两个动力学类别之间没有可测量的差异。SPCs的累积大小-频率分布在D=2–15公里范围内的斜率为γ=1.45_{-0.13}^{+0.15}（68%置信区间），对于近日点q<2天文单位的子样本，斜率变陡至2.05_{-0.38}^{+0.47}。LPCs的分布呈平滑下凹：分段幂律在约35公里处存在拐点，其下方斜率为0.92_{-0.12}^{+0.13}，上方斜率为3.68_{-1.24}^{+1.96}，而q<2天文单位的子样本在D=4–20公里范围内给出斜率为1.39_{-0.28}^{+0.35}。所有分布在拟合范围以下趋于平缓，并在约1公里处趋于平坦。我们讨论了研究结果的意义及其与失稳的海王星外天体种群模型的联系。
英文摘要
Comet nuclei preserve a record of planetesimal formation, but their sizes are difficult to measure because the nucleus is usually blended with its coma. We present a catalog of nucleus sizes for 523 comets (235 long-period and 288 short-period comets; LPCs and SPCs) from the 14.5-year WISE/NEOWISE archive, supplemented by Spitzer photometry. A coma-nucleus decomposition of the radial profiles yields conservative upper limits for all 523 comets and diameters with uncertainties for 301 (107 LPCs and 194 SPCs), with median diameters of 5.3 and 2.5 km, respectively. Nucleus colors across the four WISE bands follow the heliocentric trend expected from the transition between reflected and thermal emission, with no measurable difference between the two dynamical classes. The cumulative size-frequency distribution of the SPCs has a slope of $γ= 1.45_{-0.13}^{+0.15}$ (68% confidence interval) over $D = 2$--15 km, steepening to $2.05_{-0.38}^{+0.47}$ for the perihelion $q < 2$ au subset. The LPC distribution is smoothly concave down: a broken power law places a break near 35 km, with slopes of $0.92_{-0.12}^{+0.13}$ below and $3.68_{-1.24}^{+1.96}$ above, while the $q < 2$ au subset gives $1.39_{-0.28}^{+0.35}$ over $D = 4$--20 km. All distributions flatten below the fitted ranges and level off near 1 km. We discuss the implications of our results and their connection with models of the destabilized trans-Neptunian population.
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